Dries



G. G. FLOYD.

TRUCK $IDE FRAME. I APPLICATION FILED DEC. 15, 1919.

a SHEETS-SHEET 1.

. Patented Jan. 4,1921.

. INVENTOR George 6/70yci ATTORNEY5 G. G. FLOYD.

TRUCK SID-E FRAME- APPLICATION r|L En.oEc.1s.:1919.

mama Jam 4,1921

3SHEETS-SHEET 2.

INVENTOR 060/jge6770yd, @CW p w v ATTORNEYS G. G. FLOYD.

TRUCK SIDE FRAMEL APPLICATION, FILED DEC..15,1919.

ATTORN Y5.

Pat ented Jan. 4, 1921.

3 SHEETS-SHEET 3- INVENTOR George 6 Flayd,

UNITED PATE GEORGE e. F OYD, or me ee, ILLINOISQASSIGNOR 'ro AMERICAN STE nounnnrns, or TGHICAGO',-ILLINOIS,;A conronarron on NEW JERSEY; Y

' a/110 T AME:

"Application filed December 15, 1919. Serial No,"-344,769.

Illinois, have invented certainnew-zand useful Improvements in Truck Side "Frames, of which the following is a speoification Thisinventi'on relates to truck side frames. One object'of the inventionis towprovide a truck side frame in whichjthe stresses are more evenly distributed and balancedthan heretofore has been the case, andwhereby' such frame is materiallystrengthened at critical points without increasing the weight of the frame.v i Another object is to provide an integrally formed truck side fra-me adapted to meet the various requirements m lder severe serv ice conditions. I H v i 1 These and other. objects are accomplished by means of the truckiside frame shown on the accompanying sheets of drawings, in i i Figure 1 is a side elevation of my improved, side frame; V

Fig. 2 is a topplan view of same Fig. 3 is a-bottom plan view ofsame,

Figss, swam: a argedseotional views takemrespectively, in th pl e of lines 45-47 -'5v,;6+. -da'nd of Fig. 1; l

V r 1g. 10 1S view of my improvedsldelfram'eg and, I

Fig. ll is ,a si'de elevation, of'an ordinarycast steel side frameshowmsomewhat diagrammatically and illustrating various stresses setup inithie. frame when loaded. The cast steel sideframe! is rather .a con plicated truss structure. -.lt -is subject toa direct vertical nea nr in the weight ofthe car andlits ladi ng which load is receiyed through the bolster springs. This direct loading is. accentuated by 1 the a'ction of the bolster springs ,i L

The side frame also receives a transverse load delivered in i the; nature shocks or blows occasioned "by the longitudinal shifting of the truckfbolster which delivers the] shocks or blowsto the side frame through the column guides of the bolsters and of, th Side fram The side frame also is subjeot i to a w st ing or torsionalload. when f the :carstrikes] jor rounds curve. This l d ji especially) Specification of Letters latjent,

a vertical longitudinal, sectional e two elements 16 extend upwardly inobllque Patented two side frames is riveted securely thereto. jlnthe cast or integrally-formed side frame] in which 'all the various members of -the truss are joined rigidly, the various direct loads which produce directstresses also produce secondaryor induced stresses; At some POlIltS onithe casting the secondary an-Q192 stresses are greater an'd more serious than the primary stresses. :SOme of the portions offthe casting are subject to :twoprimary stresses and in addition several secondary stresses; jIn adding var ous,stressesalge' braically, itis found that at several points in the frame all the stresses which localize at these points happento beplus or tension stresses with no corresponding minus or compression j stresses to, lower the average Referring particularly to ig. '1' of the drawings, it Willbe noted that the sideframe there disclosed includes a compression memberl2 which'extends substantially from end to end of the casting. The compressioirmem her is connected to the tension 'member 13 i at the ends of the latter andlalso at the middle by two, columns 14. y The tension:

member l3, from a stress point of view, may

properly be divided into threeelements; one

"being that part immediately" under. the

bolsterv oaening andextending between the 1 lines 0+ and C'D,and which hereafter will be, referred to as part 15. The; other j lines from the lower ends of the columns 14 ,to the compression member 12 and connect witlithe latter I at the ends of the :casting over the supports or journals S. The load Pgtransmitted through the bolster springs tension element 15.i

1 This portion 15 of the tension member 13 load Papplied at A, and in performingth is is delivered to the side frame. at the point A, orfin the middle of the upper surface of the stresses, which produce flexune' or depression, the compression stresses being inthe upper portion of element lo and-tension stresses in the lowerportion'of said element; secondly, element 15 acts as a tension memher and accordingly is subject to tension stressesin being a part of the maintension member. Therefore, the element 15 is sub ject to bending stresses and direct tension stresses. The, inclined portions 16 of the tension member connect the ends of the beam element 15 to the ends of the compression 'member along the line KL, and are also subject to bending stresses in addition to the direct tension stresses, the former being occasioned because of the integral structure of the casting, as distinguished from a structure of like character in which the members are connected by pin joints.

Referring particularly to Fig. 11, it will be noted "that an ordinary cast steel side frame is shown which illustrates in an exaggerated manner the deformation of this casting under load, the load P being applied, as above mentioned, at the point A, and the reaction being at the points of support S. The tension element 15 will deflect or bend under this load, and the col umns 14 will be distorted by this bending, the deformation in all parts of the frame being indicated by the full lines. The end of the frame'from the point K to the point of support S is found to be a short beam subject to bendin stresses in carrying the load from point K to point S, and there is,

therefore, a resultant upbending or turn-- ing movement of the ends of the frame.

The downward deflection of the beam or tensionelement 15 and the upward defiection of the short beams immediately over the supports S--S produce in the inclined tension member portions 16 reverse bending stresses which are in addition to the straight tension stresses, the latter stresses being due to the truss action of the casting as a whole. This reverse bending action may be illustrated best by assuming that the inclined tension member portions 16 are sawed in two on the line I-J and the casting loaded at A and supported at the points S. Under such conditions, the sawed ends will assume an offset position at the line IJ, as shown by dotted lines in Fig. 11.

In view of the fact that these sawed elements move relatively to each other into an offset position, bending stresses in the inclined portions 16 of the tension members at the points KL and GH are eliminated. After the casting has assumed this oflset position, let the offset ends be moved at G and K and compression stresses at H and L. But as this inclined portion of the truss structure also is subject to tension stresses from the truss action, adding these two stresses algebraically gives high tension stresses at G and K and very low stresses at H and L, which low stresses may be either tension or compression, depending upon whether or not the tension in the member from the truss action is greater or less than the compression in the member from bending. While it is impossible, of course, for the inclined portions 16 of the tension member to be offset as hereinabove mentioned, the force or tendency is still there and is the reason for the bending stresses at G--H and KL. These bending stresses are neutral at some point between Gr-H and KL, as, for example, along line I--J.'

Therefore, at the neutral point IJ, this tension member element 16 is subject only to direct truss action tension stresses.

By developing a method of loading and testing such'castings in a manner giving results similar to actual service conditions and by the use of delicate extensometers, with which it is possible to measure the slightest stretch or shrinkage of the metal in any portion of the casting, I have been able to determine and measure the actual tension and compression stresses in these castings, and such tests'confirm the theoretical calculations that the points of highest stresses or critical points of the average size frame are at B, G and K.

As mentioned above, the tension element 15 is subject to both bending stresses, with compression at A and tension at B, and also subject to straight tension stresses over the whole section from the truss action. If these two stresses are approximately equal and are distributed equally, adding same algebraically, there would be a zero stress at the point A and a double tensionstress at the point B, therefore making point B the critical point in tension member section 15. By the same procedure, in adding algebraically the sum of the stresses from the'truss action and the compression and tension stresses from the bending, it is found that the critical points or double tension points are at G and K, while there may be zero stress points at H and L.

The line IJ, which is approximately half way between the lines GH and KL, is neutral as to bending stresses inthis member. The measured stress at IJ represents only the straight tension stress in this section resulting from the truss action of the entire casting. The difference between this average in tension stress at I-J and the stresses at G-H and KL are secondary or bending stresses.

As mentioned above, thepoints of high stress in the side frame are B, G and K. The

reasons for high tension stress at B will be considered a little more thoroughly at'this point. Considering the beam section element 15 of the tension member alone and its composite loading, it is found that there are three distinct stresses acting upon the beam in side frames as produced heretofore. First,

there is the simple load P acting at point A, it being understood that the beam is supported at its outer points DD. This load causes compression at A and tension at B. Second, there is tension as a result of the truss action which will be considered to be exerted on the longitudinal central line of the beam section 15. This tension accordingly will be exerted uniformly throughout thesection of the beam 15, thereby adding to the tension at B and reducing the compression at certain amount at A. However, there is a third stress because as side frames are constructed the tension caused by the truss action of the side frame is not along the longitudinal central axis of the beam 15', but, as a matter of fact, is considerably below same. The result, therefore, is a further bending action of the beam 15 in the same sense as caused by load P. This means that the compression at A is increased and the tension at B is increased. In all three stresses it will be seen that the tension at B is increased. It will be understood, therefore, that if the third stress or tension can be exerted above the longitudinal central. axis of beam 15, the compression at A will be reducedpand more important still the tension at will be reduced, also the bending stresses at G and K will be decreased.

The reasons why points G and K are highstress points may be analyzed from another standpoint. In Fig. 11, I have drawn line Y FN, which represents the center of gravity or neutral axis of the section. As a result of experimentation, I have found a high tension stress at the point G" and a relatively low compression stress at H. Knowing the tensile stress due to the truss action alone, as well as the total measured stresses at points G and H, it is possible to locate a point where, if an imaginary force equal to the total truss tension was assumed to act, it would produce the stress as found by measurement at point G and at point H. A series of these points being determined,- a line M-E is drawn, which line I choose to call the imaginary tension force line. The distance between the gravity axis and the tension force line at any section of the tension'eleme nt 16 is a measure of the bending stress at'that point. If it is-possible to design the casting so that the gravity axis and tension force line coincide, there will be no bending stresses in the member.

In side frames made heretofore, the gravity axis and tension force l1ne have not even approximated coincidence, and accordingly bending stresses of considerable magnitude have been developed, which in time have caused fracture ofthe castings at one or more points. study and comprehensive experimentation, I have discovered that the defect in casting "side frames lies in the improper-distribw 'tion of stressesor more particularly in not As a result of an exhaustive properly connecting the main" tension and properly extend. In designsheretofore em-.

.ployed, the stresses at certain points have been improperly transmitted through the side walls of the tension and compression members in aneffort ultimately to reach a connecting point between the tension; and.

compression members. Such designs,however, have not been satlsfactory'and in some caseshave proved fatal.

To overcome the objectionable features of such designs, such as concerted and exces- SIVG bending stresses in different parts of the frame and the improper distribution of stresses, I have provided a construction in which the gravityaxis and tensionforce line of the tension member morenearly or sub} I 1 stantially coincide andwhereby the stresses are transmitted in direct lines in and between the truckside frame tension and comaression members. i i

Referring particularly to Fig.10, which shows my improved side frame in section, it will be noted that the web 17 of the ten sion member 13 is continuous with the upper wall of the beam section 15 from a point in-' \vardly beyond the columns 14% to the coma pression member 12, and extends in 1a straight line up through the box section 19 over the associated journal box openings and 1 is connected directly to the web of the compression member at 18' over the ends or points S of support of the side frame. In

this Way the tension in element 16 01? the tension member is exerted at a point considers ably above the longitudinal central axis of tensionlelement'15,:this eccentric pullmaterially decreasing'the deflection of beam element 15- and decreasing the compression at A in the upper part of beam element and decreasing the tension at Bin the lower part of the same element. It

necessarily follows that bending stresses aregreatly decreased at'G and K, and, as a matter of fact, such bending stresses are practically neutralized or balanced by having the tension member web 17 at" the inside of the frame and directly connecting said web to the web of the /compression member wherein the bending stresses at the point 18 at each end of the frame. In other words, the gravity axis and the force tension line more nearly coincide and particularly so at the points (line CD) where the inclined tension elements 16 meet the beam element 15, as shown in Fig. 10. These conclusions are based upon actual .ligures obtained in extensive experimental work and testing operations.

The beam portion 15 of the tension memher is made in a box shape having a top, bottom and two sides for increasing the strength of the section. It will be noted also that each of the ends of the side frame over the journal boxes is greatly reinforced against bending stresses by having three superimposed webs; namely, the webs of the tension and compression members and the web forming the upper wall 20 of the pedestal jaw. The inclined tension member portions are U-shaped in section. For the reasons given, the main web 17 is at the upper or inner side of said tension member, with the channel openin formed between the two side walls on the lower and outer side.

I claim:

1. A truck side frame including tension and compression members and columns therebetween all cast in a single piece whereby and wherein the bending stresses ordinarily -would be greatest and excessive at the upper side of the tension member directly outwardly from the columns and at the under side of said tension member directly inwardly from the journal box portions, said tension member being channel-shaped in section and having its web at the upper side of the tension member to distribute the tension stresses in the tension member in a manner to reduce the bending stresses at the points mentioned.

2. A truck side frame including tension and compression members and column members all cast in a single piece whereby and ordinarily would be greatest and excessive at two points spaced along the length of the tension member and on different sides thereof, said tension member being channel-shaped in section and having its web at the upper side of the tension member to distribute the tension stresses so that the greater part thereof are exerted through the upper web side of the tension member to reduce the bending stresses at the points mentioned.

8. A trucl: side frame including tension and compression members and column members all cast in a single piece whereby and wherein the bending stresses ordinarily would be greatest and excessive at the up side and continuous from a point between the columns and the compression member whereby the tension stresses in the tension member are transmitted primarily through the upper web side of the tension member to reduce the bending stresses at the points mentioned.

4%. A. truck side frame including tension and compression members and icolumns therebetween all cast in a single piece whereby and wherein the tension stresses ordinarily would be greatest and excessive at the under side of the tension member between the columns, at the upper side of the tension member directly outwardly from the columns and at the under side of the tension member directly inwardly from the ournal box portions, said tension member being channel-shaped in section and having its web at the upper side of the tension member whereby the tension stresses in the tension member are transmitted primarily through the upper web side of the tension member to counteract and reduce the tension at the points of greatest tension mentioned.

5. A truck side frame including inclined tension and compression members and bolster column members all cast in a single piece whereby and wherein the bending stresses ordinarily would be excessive at points at the upper side of the tension member directly outwardly from the columns and at the under side of the tension member directly inwardly from the journal box receiving portions, said tension member being constructed with its metal arranged in a manner whereby the tension stresses will be so distributed as to reduce the bending stresses at the points mentioned.

6. A truck side frame including integrally formed tension and compression members both U-shaped in section, the tension member having inclined portions, the webs of which are continuous throughout the inclined portions, extend through the box section over the journal box openings, and are connected directly to the web of the compression member whereby bending stresses in the inclined portions of said tension member are reduced.

7. A truck side frame including tension and compression members and column members therebetween all cast in a single piece whereby and wherein the tension stresses ordinarily would be greatest and excessive at the under side of the tension member between the columns, at the upper side of the tension member directly outwardly from the columns and at the under side 01'? the tension member directly inwardly from the journal receiving portions, said tension member between the columns being walled on all sides and the portions outwardly from the columns being channel-shaped in section and each having its web at the upper side of the tension member whereby the tension stresses in the tension member are carried in a manner to counteract and reduce the tension at the points of greatest tension mentioned.

8. A truck side frame including tension and compression members cast in a single piece wherein the bending stresses ordinarily would be excessive at the upper side of the tension member directly outwardly from the columns and at the under side of the tension member directly inwardly from the journal box receiving portions, said tension and compression members both being U-shaped in section and having their 'webs at their upper sides, respectively, for reducing the bending stresses in said tension member.

9. A truck side frame including tension and compression members and column members therebetween all cast in a single piece whereby and wherein tension stresses ordinarily would be greatest and excessive at spaced points on opposite sides of the tension member along the length thereof, said tension member between said column members being of a box-like structure and outwardly beyond said column members being channel-shaped in section and having the web at the upper side of the tension member for distributing-the tension stresses in a manner such that said tension stresses are reduced at the points of greatest tension mentioned.

10. A truck side frame including integrally formed tension and compression members both U-shaped in section, the tension member having inclined portions the webs of which are continuous throughout the inclined portions and are connected directly to the web of the compression member approximately over the center line of the journal boxes whereby stresses in the inclined portionbofjthe tension member are the journal boxes whereby stressesin thein- 1 clined portion of the tension member are re duced, there being an addltlonal web immediately over each ournal boxto resist local bending stresses directly inwardly.

from the journal box receiving portion.

including inte- 12. A truck side frame including tension and compression members cast in 'a single piece, the middle portion of the tension member, at itspoint of juncture with tension member portions extending outwardly therefrom, having afneutral axis belowthe neutral axes of said outwardly extending 65' tension member portions whereby bending stresses in the tension member are minimized; i i

' 13. A truck side frame including tension and compression members cast in single piece, the middle portion of the tension member being/of a box-like structure and the portions extending outwardly therefrotrn being channel-shaped in section with the web at the upper side whereby the neutral axis of the middleportion at itspoints of juncture with the channel-shaped portions is below the neutral. axes of said channelshaped portions whereby the bending stresses in the tension member are minimized.

Signed at Chicago, Illinois, thisllth of December, 1919.

- GEORGE e.- FLOYD. 

